At 16:16 9/14/95 -0400, Jonathan Shapiro wrote:
>Why does going to a 64 bit implementation for *data* registers
>necessarily imply that a domain requires more/larger authorities? The
>two would seem to be orthogonal issues.
64 bit data registers may give you more bits in the entry/exit blocks to use to specify received/passed key slots. It is not clear what domains really need, so the discussion is an excellent one to hold in a bar.
>
> >Thanks for the clarification about the domain creator. Any reason you
> >can see why the domain tool should not rescind the component nodes
> >before constructing the domain?
>
> Unneeded overhead.
>
>Ahh, but it simplifies the domain prepare code to do so, which
>speeds context switching, which speeds message passing, which
>speeds....
Significantly only if you prepare (and presumably unprepare) domains often. It may be a net loss since the checking in the prepare path is really cheap (and may be free if you have to do it for other reasons, including correctness paranoia). In any case, it is down in the noise, well below the effects of higher level language vs. assembler and other icons in the computer-science world.
Bill